1. Field of the Invention
The present invention relates to a projector device and a projector system having an irregular color and irregular luminance correction circuit.
The present application claims priority of Japanese Patent Application No. 2001-336556 filed on Nov. 1, 2001, which is hereby incorporated by reference.
2. Description of Related Art
Generally, in a liquid crystal projector which is a typical display device, caused by an irregular liquid crystal cell gap thickness of each liquid crystal module for Red, Green and Blue (hereinafter may be referred simply to as R, B, and G), an irregularity in a panel surface and a like, respective contrasts for R, G, and B are different. Therefore, an irregular color and an irregular luminance occur in a display image made by transmitting through three liquid modules (R, B, and G) and by synthesis projecting.
Also, in a projector, an irregular color and an irregular luminance occur caused by a characteristic of an angle of visibility in a screen.
To prevent these disadvantages, for example, a technique disclosed in Japanese Patent Application Laid-open No. Hei 09-146496 (hereinafter referred to as prior art) is known.
In a projector using this prior art, as corrections for an irregular color and an irregular luminance caused by liquid crystal modules and for an irregular color and an irregular luminance caused by a characteristic of an angle of visibility of a screen, an image to be displayed in a screen is corrected through the screen, and a correction amount to be corrected is stored in a memory as a correction value at factory adjustment.
However, in the above-described technique, when the image displayed on the screen is corrected, the adjustment for the irregular color and the irregular luminance caused by the liquid crystal modules and the adjustment for the irregular color and the irregular luminance caused by the characteristic of the angle of visibility of the screen are performed at the same time, and a single correction value is stored at factory shipping. Therefore, when the screen whose characteristic of the angle of visibility is remarkably different after shipping is used, the irregular color and the irregular luminance occur. To prevent the irregular color and the irregular luminance, the correction value must be adjusted again at the factory.
In view of the above, it is an object of the present invention to provide a projector device and a projector system capable of solving an irregular color and an irregular luminance easily without factory adjustment though a screen is changed to another screen having a different characteristic of an angle of visibility after shipping.
According to a first aspect of the present invention, there is provided a projector including:
a display device for displaying an image;
an optical system for enlarged-projecting the image displayed on the display device by a light from a light source;
a memory for storing a luminance distribution value at each point in a projected image when the image is projected on a screen having no characteristic of angle of visibility, a luminance inclination value at each point of the projected image when the image is projected on the screen having no characteristic of angle of visibility, a screen distribution value which is a luminance at each point in the projected image when the image is projected on a screen having a characteristic of angle of visibility after correcting irregular color and irregular luminance by the display device and the optical system, and a correction value to be an image signal level in which a product of the luminance distribution value and the screen distribution value at the each point is equal to the luminance inclination value;
an internal central processing unit for calculating the correction value;
an external interface for inputting data into the memory in accordance with instructions of the internal central processing unit; and
an irregular color and irregular luminance correction circuit for obtaining an interpolation value based on the correction value read from the memory and for correcting the irregular color and the irregular luminance on the screen based on the correction value and the interpolation value.
In the foregoing first aspect, a preferable mode is one that wherein, for the plurality of screens of which characteristics of angles of visibility are different, is so configured as to store previously the screen distribution values in the memory, and to calculate the correction value corresponding to each of the screen distribution values and store previously the calculated correction value in the memory.
Another preferable mode is one wherein for the screen of which the characteristic of angle of visibility is not stored, the screen distribution value is updated by using the external interface and the internal central processing unit, and the correction value is further updated.
Still another preferable mode is one wherein the screen is a transparent screen, and a reflective mirror for reflecting the image to be projected to the transparent screen is provided.
According to a second aspect of the present invention, there is provided a projector including:
a display device for displaying an image;
an optical system for enlarged-projecting of the image displayed on the display device by a light from a light source;
a memory for storing a luminance distribution value at each point in a projected image when the image is projected on a screen having no characteristic of angle of visibility, a luminance inclination value at each point of the projected image when the image is projected on the screen having no characteristic of angle of visibility, a screen distribution value which is a luminance at each point in the projected image when the image is projected on a screen having a characteristic of angle of visibility after correcting irregular color and irregular luminance by the display
In the foregoing first aspect, a preferable mode is one that wherein, for the plurality of screens of which characteristics of angles of visibility are different, is so configured as to store previously the screen distribution values in the memory, and to calculate the correction value corresponding to each of the screen distribution values and store previously the calculated correction value in the memory.
Another preferable mode is one wherein for the screen of which the characteristic of angle of visibility is not stored, the screen distribution value is updated by using the external interface and the internal central processing unit, and the correction value is further updated.
Still another preferable mode is one wherein the screen is a transparent screen, and a reflective mirror for reflecting the image to be projected to the transparent screen is provided.
According to a second aspect of the present invention, there is provided a projector including:
a display device for displaying an image;
an optical system for enlarged-projecting of the image displayed on the display device by a light from a light source;
a memory for storing a luminance distribution value at each point in a projected image when the image is projected on a screen having no characteristic of angle of visibility, a luminance inclination value at each point of the projected image when the image is projected on the screen having no characteristic of angle of visibility, a screen distribution value which is a luminance at each point in the projected image when the image is projected on a screen having a characteristic of angle of visibility after correcting irregular color and irregular luminance by the display device and the optical system, and a correction value to be an image signal level in which a product of the luminance distribution value and a the screen distribution value at the each point is equal to the luminance inclination value;
a central processing unit for calculating the correction value;
an external interface for inputting data into the memory in accordance with instructions of the central processing unit; and
an irregular color and irregular luminance correction circuit for obtaining an interpolation value based on the correction value read from the memory and for correcting the irregular color and the irregular luminance on the screen based on the correction value and the interpolation value.
In the foregoing second aspect, a preferable mode is one wherein a projector device is made up of the display device the optical system, the memory, and the irregular color and irregular luminance correction circuit, and wherein the central processing unit and the external interface are used as external devices.
Another preferable mode is one that wherein, for the plurality of screens of which characteristics of angles of visibility are different, is so configured as to store previously the screen distribution values in the memory, and to calculate the correction value corresponding to each of the screen distribution values and store previously the calculated correction value in the memory.
Still another preferable mode is one wherein, for the screen of which the characteristic of angle of visibility is not stored, the screen distribution value is updated by using the external interface and the central processing unit, and the correction value is further updated.
A further preferable mode is one wherein the screen is a transparent screen, and a reflective mirror for reflecting the image to be projected to the transparent screen is provided.
With these configurations, a plurality of screen distribution values for a plurality of screens whose angles of visibility are different are previously prepared, a rear projector capable of easily solving irregular color and irregular luminance can be provided by changing the screen distribution value only, without factory adjustment even if a screen is changed to another screen whose characteristic of an angle of visibility is different after factory shipping.
Also, when a projector is a rear type, a luminance distribution value depending on a display device and the screen distribution value depending on a screen are stored independently, thereby performing an irregular color and irregular luminance correction of front/rear at the same step.